The Vostok (Russian: Восток, translated as East) was a type of spacecraft built by the Soviet Union's space programme for human spaceflight.

The craft consisted of a spherical descent module (mass 2.46 tonnes, diameter 2.3 meters), which housed the cosmonaut, instruments and escape system, and a conical instrument module (mass 2.27 tonnes, 2.25 m long, 2.43 m wide), which contained propellant and the engine system. On reentry, the cosmonaut would eject from the craft at about 7,000 m (23,000 ft) and descend via parachute, while the capsule would land separately.

The Vostok capsule did not have any thrusters. As such, the reentry path and orientation could not be controlled after the capsule had separated from the engine system. This meant that the capsule had to be protected from friction heat on all sides, thus explaining the spherical design (as opposite to Project Mercury's conical design), which allows for maximum volume, while minimizing the external surface. The only way for some control of the capsule was in the positioning of the heavy equipment, which was placed in such a manner that maximized the chance of the cosmonaut enduring g-forces while in a horizontal position. Even then, the cosmonaut experienced 8 to 9g.

The Vostok spacecraft was originally designed for use both as a camera platform (for the Soviet Union's first spy satellite program, Zenit) and as a manned spacecraft. This dual-use design was crucial in gaining Communist Party support for the program. The basic Vostok design has remained in use for some forty years, gradually adapted for a range of other unmanned satellites. The descent module design was reused, in heavily-modified form, by the Voskhod programme.

There were several models of the Vostok leading up to the manned version:

• Vostok 1K - prototype spacecraft. Used to test basic systems and prove the concept.
• Vostok 2K - photo-reconnaissance and signals intelligence spacecraft . Later named Zenit-2.
• Vostok 3K - Manned spacecraft.

  Vostok 3KA spacecraft specifications

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  Reentry Module: Vostok SA. Also known as: Spuskaemiy apparat - 'Sharik' (sphere).

  • Crew Size: 1
  • Length: 2.3 m
  • Diameter: 2.3 m
  • Mass: 2,460 kg
  • Heat Shield Mass: 837 kg
  • Recovery equipment: 151 kg
  • Parachute deploys at 2.5 km altitude
  • Crew seat and provisions: 336 kg
  • Crew ejects at 7 km altitude
  • Ballistic reentry acceleration: 8 g (78 m/s²)

  Equipment Module: Vostok PA. Also known as: Priborniy otsek.

  • Length: 2.25 m
  • Diameter: 2.43 m
  • Mass: 2,270 kg
  • Equipment in pressurized compartment
  • RCS Propellants: Cold gas (nitrogen)
  • RCS Propellants: 20 kg
  • Main Engine (TDU): 397 kg
  • Main Engine Thrust: 15.83 kN
  • Main Engine Propellants: Nitrous oxide/amine
  • Main Engine Propellants: 275 kg
  • Main Engine Isp: 266 s (2.61 kN·s/kg)
  • Main Engine Burn Time: 1 minute (typical retro burn = 42 seconds)
  • Spacecraft delta v: 155 m/s
  • Electrical System: Batteries
  • Electric System: 0.20 average kW
  • Electric System: 24.0 kW·h
  • Total Mass:4,730 kg
  • Endurance: Supplies for 10 days in orbit
  • Launch Vehicle: Vostok 8K72K
  • Typical orbit: 177 km x 471 km, 64.9 inclinaton

  See also

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  • Vostok 1
  • Vostok rocket

  External links

  • Vostok Specifications

  Manned spacecraft | Vostok programme | Russian spacecraft

  Wostok (Raumkapsel) | Vostok | Vostok (pesawat) | Восток (КА)